Playing Devil's Advocate with Supermassive Black Hole Binaries
Open Access
- Author:
- Kaldor, Mary
- Area of Honors:
- Astronomy and Astrophysics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Michael Eracleous, Thesis Supervisor
Alexander Wolszczan, Thesis Honors Advisor - Keywords:
- Supermassive black hole binaries
accretion disk
line profile
SDSS
Python
Fortran
black hole
binary
quasar
Pearson skewness coefficient
peak velocity shift - Abstract:
- Supermassive black hole binaries form when massive galaxies merge, and their respective black holes fall to the center of their “gravitational well”. Their infalling towards one other results in an orbital motion that drags gas and dust with each object; this motion creates redshifting and blueshifting within the line profiles of the merger. A collection of line profiles from the Sloan Dig- ital Sky Survey (SDSS) quasars displayed this broadening of the Hβ emission line. These lines had velocity dispersions larger than 1000 km/s from the rest frame wavelength, which promoted their candidacy as binaries. I aim to evaluate the 88 current binary candidates. I do this by comparing simulated line profiles based on a single-disk model to the observed line profiles. From there, I define viable parameter islands and utilize those to create a larger randomized pool of single-disk Pearson skewness coefficients against peak velocity shifts. When I examine the observed Pearson skewness coefficients and peak velocity shifts against those of the simulated line profiles, I find that although there is some overlap, most of the observed data cannot be mimicked by the single- disk model. The observed data points that do overlap may be discarded as they are no longer ideal binary candidates. The rest of the observed data may continue to be observed under the binary hypothesis; while binary activity is not the only viable explanation, it has not yet been disproven as the reason for the observed line profile shifts.